Canada's enormous size and long history have produced mysteries ranging from unexplained disappearances to archaeological puzzles that have lasted for generations. Some cases have attracted treasure hunters, while others remain active police investigations or subjects of historical research. From Nova Scotia to the Arctic, these six mysteries show how difficult it can be to separate what is known from what people desperately want to know.

For decades, corporate travel departments have managed one number above all others: money. Employees could fly to a conference, visit a client, or bring a remote team together as long as the trip fit the company’s financial rules and someone was willing to pay for it. Increasingly, companies are adding another number to the equation: the greenhouse gas emissions created by the journey.

If an intelligent alien arrived on Earth, you can imagine what scientists would ask first. But when a Vatican astronomer faced a room full of reporters, someone asked something very different: would he baptize an extraterrestrial? His answer got a laugh. Then it made headlines.